ABSTRACT
Salivary gland dysfunction is a common side effect of cancer treatments. Salivary function plays key roles in critical daily activities. Consequently, changes in salivary function can profoundly impair quality of life for cancer patients. We discuss salivary gland anatomy and physiology to understand how anticancer therapies such as chemotherapy, bone marrow transplantation, immunotherapy, and radiation therapy impair salivary function. We discuss approaches to quantify xerostomia in the clinic, including the advantages and limitations of validated quality-of-life instruments and approaches to directly measuring salivary function. Current and emerging approaches to treat cancer therapy-induced dry mouth are presented using radiation-induced salivary dysfunction as a model. Limitations of current sialagogues and salivary analogues are presented. Emerging approaches, including cellular and gene therapy and novel pharmacologic approaches, are described.
Subject(s)
Neoplasms , Salivary Glands , Xerostomia , Humans , Salivary Glands/physiopathology , Salivary Glands/metabolism , Salivary Glands/pathology , Neoplasms/therapy , Xerostomia/therapy , Xerostomia/etiology , Xerostomia/physiopathology , Radiotherapy/adverse effects , Quality of Life , Animals , Immunotherapy/adverse effects , Antineoplastic Agents/adverse effectsABSTRACT
Salivary proteins of insect herbivores can suppress plant defenses, but the roles of many remain elusive. One such protein is glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the saliva of the Recilia dorsalis (RdGAPDH) leafhopper, which is known to transmit rice gall dwarf virus (RGDV). Here we show that RdGAPDH was loaded into exosomes and released from salivary glands into the rice phloem through an exosomal pathway as R. dorsalis fed. In infected salivary glands of R. dorsalis, the virus upregulated the accumulation and subsequent release of exosomal RdGAPDH into the phloem. Once released, RdGAPDH consumed H2O2 in rice plants owing to its -SH groups reacting with H2O2. This reduction in H2O2 of rice plant facilitated R. dorsalis feeding and consequently promoted RGDV transmission. However, overoxidation of RdGAPDH could cause potential irreversible cytotoxicity to rice plants. In response, rice launched emergency defense by utilizing glutathione to S-glutathionylate the oxidization products of RdGAPDH. This process counteracts the potential cellular damage from RdGAPDH overoxidation, helping plant to maintain a normal phenotype. Additionally, salivary GAPDHs from other hemipterans vectors similarly suppressed H2O2 burst in plants. We propose a strategy by which plant viruses exploit insect salivary proteins to modulate plant defenses, thus enabling sustainable insect feeding and facilitating viral transmission.
Subject(s)
Hemiptera , Hydrogen Peroxide , Oryza , Plant Diseases , Saliva , Animals , Hemiptera/virology , Hydrogen Peroxide/metabolism , Oryza/virology , Oryza/metabolism , Plant Diseases/virology , Saliva/metabolism , Saliva/virology , Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism , Salivary Glands/virology , Salivary Glands/metabolism , Insect Proteins/metabolism , Insect Proteins/genetics , Insect Vectors/virology , Phloem/virology , Phloem/metabolism , Reoviridae/physiology , Glutathione/metabolism , Salivary Proteins and Peptides/metabolism , Plant Viruses/physiology , Plant Defense Against HerbivoryABSTRACT
Venomous marine gastropods of the superfamily Conoidea possess a rich arsenal of toxins, including neuroactive toxins. Venom adaptations might have played a fundamental role in the radiation of conoideans; nevertheless, there is still no knowledge about the venom of the most diversified family of the group: Raphitomidae Bellardi, 1875. In this study, transcriptomes were produced from the carcase, salivary glands, and proximal and distal venom ducts of the northeastern Atlantic species Raphitoma purpurea (Montagu, 1803). Using a gut barcoding approach, we were also able to report, for the first time, molecular evidence of a vermivorous diet for the genus. Transcriptomic analyses revealed over a hundred putative venom components (PVC), including 69 neurotoxins. Twenty novel toxin families, including some with high levels of expansion, were discovered. No significant difference was observed between the distal and proximal venom duct secretions. Peptides related to cone snail toxins (Cerm06, Pgam02, and turritoxin) and other venom-related proteins (disulfide isomerase and elevenin) were retrieved from the salivary glands. These salivary venom components may constitute ancestral adaptations for venom production in conoideans. Although often neglected, salivary gland secretions are of extreme importance for understanding the evolutionary history of conoidean venom.
Subject(s)
Mollusk Venoms , Snails , Animals , Mollusk Venoms/genetics , Snails/genetics , Transcriptome , Salivary Glands/metabolismABSTRACT
INTRODUCTION: The therapeutic interest of targeting B-cell activating factor (BAFF) in Sjögren's disease (SjD) can be suspected from the results of two phase II clinical trials but has not been evaluated in an animal model of the disease. We aimed to evaluate the therapeutic efficacy of this strategy on dryness and salivary gland (SG) infiltrates in the NOD mouse model of SjD. MATERIAL AND METHODS: Female NOD mice between ages 10 and 18 weeks were treated with a BAFF-blocking monoclonal antibody, Sandy-2 or an isotype control. Dryness was measured by the stimulated salivary flow. Salivary lymphocytic infiltrates were assessed by immunohistochemistry. Blood, SGs, spleen and lymph-node lymphocyte subpopulations were analysed by flow cytometry. SG mRNA expression was analysed by transcriptomic analysis. RESULTS: BAFF inhibition significantly decreased SG lymphocytic infiltrates, which was inversely correlated with salivary flow. The treatment markedly decreased B-cell number in SGs, blood, lymph nodes and spleen and increased Foxp3+ regulatory and CD3+CD4-CD8- double negative T-cell numbers in SGs. CONCLUSION: A monoclonal antibody blocking BAFF and depleting B cells had therapeutic effectiveness in the NOD mouse model of SjD. The increase in regulatory T-lymphocyte populations might underlie the efficacy of this treatment.
Subject(s)
B-Cell Activating Factor , B-Lymphocytes , Disease Models, Animal , Mice, Inbred NOD , Sjogren's Syndrome , Animals , B-Cell Activating Factor/antagonists & inhibitors , B-Cell Activating Factor/metabolism , Sjogren's Syndrome/immunology , Mice , Female , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Salivary Glands/pathology , Salivary Glands/metabolism , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/pharmacology , Lymphocyte DepletionABSTRACT
Intermittent fasting exerts a profound beneficial influence on a spectrum of diseases through various mechanisms including regulation of immune responses, elimination of senescent- and pathogenic cells and improvement of stem cell-based tissue regeneration in a disease- and tissue-dependent manner. Our previous study demonstrated that alternate-day fasting (ADF) led to alleviation of xerostomia and sialadenitis in non-obese diabetic (NOD) mice, a well-defined model of Sjögren's syndrome (SS). This present study delved into the previously unexplored impacts of ADF in this disease setting and revealed that ADF increases the proportion of salivary gland stem cells (SGSCs), defined as the EpCAMhi cell population among the lineage marker negative submandibular gland (SMG) cells. Furthermore, ADF downregulated the expression of p16INK4a, a cellular senescence marker, which was concomitant with increased apoptosis and decreased expression and activity of NLRP3 inflammasomes in the SMGs, particularly in the SGSC-residing ductal compartments. RNA-sequencing analysis of purified SGSCs from NOD mice revealed that the significantly downregulated genes by ADF were mainly associated with sugar metabolism, amino acid biosynthetic process and MAPK signaling pathway, whereas the significantly upregulated genes related to fatty acid metabolic processes, among others. Collectively, these findings indicate that ADF increases the SGSC proportion, accompanied by a modulation of the SGSC property and a switch from sugar- to fatty acid-based metabolism. These findings lay the foundation for further investigation into the functionality of SGSCs influenced by ADF and shed light on the cellular and molecular mechanisms by which ADF exerts beneficial actions on salivary gland restoration in SS.
Subject(s)
Fasting , Mice, Inbred NOD , Salivary Glands , Sjogren's Syndrome , Stem Cells , Animals , Sjogren's Syndrome/metabolism , Sjogren's Syndrome/pathology , Sjogren's Syndrome/genetics , Mice , Salivary Glands/metabolism , Salivary Glands/pathology , Stem Cells/metabolism , Submandibular Gland/metabolism , Submandibular Gland/pathology , Disease Models, Animal , Female , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Inflammasomes/metabolism , ApoptosisABSTRACT
The Egyptian tortoise (Testudo kleinmanni) is remarkably adapted to its harsh desert environment, a characteristic that is crucial for its survival under extreme conditions. This study was aimed at providing a deeper understanding of the lingual salivary gland structures in the Egyptian tortoise and examining how these structures help the tortoise manage hydration and nutrition in arid conditions. Utilizing a combination of light microscopy and immunofluorescence, this research introduced pioneering methods involving seven different antibodies, marking a first in the study of reptilian salivary glands. Our investigations categorized the tortoise's salivary glands into papillary and non-papillary types. The papillary glands were further classified into superficial, deep, interpapillary, and intraepithelial salivary glands, while non-papillary glands included superficial and deep lingual types. Structurally, these glands are organized into lobules, delineated by interlobular septa, and are equipped with a duct system comprising interlobular, intercalated, and main excretory ducts with gland openings on the tongue's surface and the papillae surfaces. Notably, the superficial glands displayed both tubuloalveolar and acinar configurations, whereas the deep lingual glands were exclusively acinar. Immunofluorescence results indicated that α-smooth muscle actin (α-SMA) was prevalent in myoepithelial cells, myofibroblasts, and blood vessels, suggesting their integral role in glandular function and support. E-cadherin was predominantly found in epithelial cells, enhancing cell adhesion and integrity, which are critical for efficient saliva secretion. Importantly, Mucin 1 (MUC1) and Mucin 5B (MUC5B) staining revealed that most glands were mucous in nature, with MUC5B specifically marking mucin within secretory cells, confirming their primary function in mucous secretion. PDGFRα and CD34 highlighted the presence of telocytes and stromal cells within the glandular and interlobular septa, indicating a role in structural organization and possibly in regenerative processes. Cytokeratin 14 expression was noted in the basal cells of the glands, underscoring its role in upholding the structural foundation of the epithelial barrier. In conclusion, this detailed morphological and immunological characterization of the Egyptian tortoise's salivary glands provides new insights into their complex structure and essential functions. These findings not only enhance our understanding of reptilian physiology but also underline the critical nature of salivary glands in supporting life in arid environments. This study's innovative use of a broad range of immunofluorescence markers opens new avenues for further research into the adaptive mechanisms of reptiles.
Subject(s)
Fluorescent Antibody Technique , Salivary Glands , Turtles , Animals , Turtles/metabolism , Salivary Glands/metabolism , Salivary Glands/cytology , Tongue/cytology , Tongue/metabolism , EgyptABSTRACT
BACKGROUND: Hyposalivation is treated using oral cholinergic drugs; however, systemic side effects occasionally lead to discontinuation of treatment. We aimed to investigate the effects of transdermal pilocarpine on the salivary gland skin on saliva secretion and safety in rats. METHODS: Pilocarpine was administered to rats orally (0.5 mg/kg) or topically on the salivary gland skin (5 mg/body). Saliva volume, the number of sweat dots, and fecal weight were measured along with pilocarpine concentration in plasma and submandibular gland tissues. RESULTS: Saliva volume significantly increased 0.5 h after oral administration and 0.5, 3, and 12 h after topical administration. Fecal weight and sweat dots increased significantly 1 h after oral administration; however, no changes were observed after topical application. The pilocarpine concentration in the submandibular gland tissues of the topical group was higher than that in the oral group at 0.5, 3, and 12 h of administration. CONCLUSIONS: Pilocarpine application to salivary gland skin persistently increased salivary volume in rats without inducing sweating or diarrhea. Transdermal pilocarpine applied to the skin over the salivary glands may be an effective and safe treatment option for hyposalivation.
Subject(s)
Administration, Cutaneous , Pilocarpine , Salivary Glands , Salivation , Xerostomia , Pilocarpine/administration & dosage , Pilocarpine/pharmacology , Animals , Salivation/drug effects , Rats , Male , Salivary Glands/drug effects , Salivary Glands/metabolism , Xerostomia/chemically induced , Xerostomia/drug therapy , Muscarinic Agonists/administration & dosage , Muscarinic Agonists/pharmacology , Saliva/metabolism , Saliva/chemistry , Administration, Oral , Submandibular Gland/drug effects , Submandibular Gland/metabolism , Rats, Sprague-DawleyABSTRACT
Heparan sulfate (HS) regulation of FGFR function, which is essential for salivary gland (SG) development, is determined by the immense structural diversity of sulfated HS domains. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS), and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs) that produce basement membrane (BM) and are a growth factor signaling hub. Hs3st3a1;Hs3st3b1 double-knockout (DKO) mice generated to investigate 3-O-HS regulation of MEC function and growth factor signaling show loss of specific highly 3-O-HS and increased FGF/FGFR complex binding to HS. During development, this increases FGFR-, BM- and MEC-related gene expression, while in adult, it reduces MECs, increases BM and disrupts acinar polarity, resulting in salivary hypofunction. Defined 3-O-HS added to FGFR pulldown assays and primary organ cultures modulates FGFR signaling to regulate MEC BM synthesis, which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.
Subject(s)
Basement Membrane , Cell Differentiation , Epithelial Cells , Heparitin Sulfate , Mice, Knockout , Salivary Glands , Signal Transduction , Sulfotransferases , Animals , Heparitin Sulfate/metabolism , Basement Membrane/metabolism , Salivary Glands/metabolism , Salivary Glands/cytology , Sulfotransferases/metabolism , Sulfotransferases/genetics , Mice , Epithelial Cells/metabolism , Epithelial Cells/cytology , Receptors, Fibroblast Growth Factor/metabolism , Receptors, Fibroblast Growth Factor/genetics , Male , Fibroblast Growth Factors/metabolismABSTRACT
Sjögren's Syndrome (SS) is an autoimmune disorder characterized by dysfunction of exocrine glands. Primarily affected are the salivary glands, which exhibit the most frequent pathological changes. The pathogenesis involves susceptibility genes, non-genetic factors such as infections, immune cells-including T and B cells, macrophage, dendritic cells, and salivary gland epithelial cells. Inflammatory mediators such as autoantibodies, cytokines, and chemokines also play a critical role. Key signaling pathways activated include IFN, TLR, BAFF/BAFF-R, PI3K/Akt/mTOR, among others. Comprehensive understanding of these mechanisms is crucial for developing targeted therapeutic interventions. Thus, this study explores the cellular and molecular mechanisms underlying SS-related salivary gland damage, aiming to propose novel targeted therapeutic approaches.
Subject(s)
Salivary Glands , Signal Transduction , Sjogren's Syndrome , Sjogren's Syndrome/immunology , Sjogren's Syndrome/pathology , Sjogren's Syndrome/metabolism , Sjogren's Syndrome/genetics , Sjogren's Syndrome/etiology , Humans , Salivary Glands/pathology , Salivary Glands/metabolism , Salivary Glands/immunology , Animals , Cytokines/metabolismABSTRACT
Adenoid cystic carcinoma (AdCC) is a slow-growing salivary gland malignancy that relapses frequently. AdCCs of the submandibular gland exhibit unique differences in prognosis and treatment response to adjuvant radiotherapy compared to other sites, yet the role of tumor anatomic subsite on gene expression and tumor immune microenvironment (TIME) composition remains unclear. We used 87 samples, including 48 samples (27 AdCC and 21 normal salivary gland tissue samples) from 4 publicly available AdCC RNA sequencing datasets, a validation set of 33 minor gland AdCCs, and 39 samples from an in-house cohort (30 AdCC and 9 normal salivary gland samples). RNA sequencing data were used for single sample gene set enrichment analysis and TIME deconvolution. Quantitative PCR and multiplex immunofluorescence were performed on the in-house cohort. Wilcoxon rank-sum, nonparametric equality-of-medians tests and linear regression models were used to evaluate tumor subsite differences. AdCCs of different anatomic subsites including parotid, submandibular, sublingual, and minor salivary glands differed with respect to expression of several key tumorigenic pathways. Among the three major salivary glands, the reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway signature was significantly underexpressed in AdCC of submandibular compared to parotid and sublingual glands while this association was not observed among normal glands. Additionally, the NRF2 pathway, whose expression was associated with favorable overall survival, was overexpressed in AdCCs of parotid gland compared to minor and submandibular glands. The TIME deconvolution identified differences in CD4+ T cell populations between AdCC of major and minor glands and natural killer (NK) cells among AdCC of minor, submandibular, and parotid glands while plasma cells were enriched in normal submandibular glands compared to other normal gland controls. Our data reveal key molecular differences in AdCC of different anatomic subsites. The ROS and NRF2 pathways are underexpressed in submandibular and minor AdCCs compared to parotid gland AdCCs, and NRF2 pathway expression is associated with favorable overall survival. The CD4+ T, NK, and plasma cell populations also vary by tumor subsites, suggesting that the observed submandibular AdCC tumor-intrinsic pathway differences may be responsible for influencing the TIME composition and survival differences.
Subject(s)
Carcinoma, Adenoid Cystic , Salivary Gland Neoplasms , Tumor Microenvironment , Humans , Carcinoma, Adenoid Cystic/pathology , Carcinoma, Adenoid Cystic/immunology , Carcinoma, Adenoid Cystic/metabolism , Carcinoma, Adenoid Cystic/genetics , Salivary Gland Neoplasms/pathology , Salivary Gland Neoplasms/immunology , Salivary Gland Neoplasms/genetics , Salivary Gland Neoplasms/metabolism , Salivary Gland Neoplasms/mortality , Male , Female , Tumor Microenvironment/immunology , Middle Aged , Aged , Gene Expression Regulation, Neoplastic , Adult , Salivary Glands/pathology , Salivary Glands/metabolism , Salivary Glands/immunology , PrognosisABSTRACT
Introduction: Salivary gland dysfunction, often resulting from salivary gland obstruction-induced inflammation, is a prevalent condition. Corticosteroid, known for its anti-inflammatory and immunomodulatory properties, is commonly prescribed in clinics. This study investigates the therapeutic implications and potential side effects of dexamethasone on obstructive sialadenitis recovery using duct ligation mice and salivary gland organoid models. Methods: Functional and pathological changes were assessed after administering dexamethasone to the duct following deligation 2 weeks after maintaining ligation of the mouse submandibular duct. Additionally, lipopolysaccharide- and tumor necrosis factor-induced salivary gland organoid inflammation models were established to investigate the effects and underlying mechanisms of action of dexamethasone. Results: Dexamethasone administration facilitated SG function restoration, by increasing salivary gland weight and saliva volume while reducing saliva lag time. Histological evaluation revealed, reduced acinar cell atrophy and fibrosis with dexamethasone treatment. Additionally, dexamethasone suppressed pro-inflammatory cytokines IL-1ß and TNF expression. In a model of inflammation in salivary gland organoids induced by inflammatory substances, dexamethasone restored acinar markers such as AQP5 gene expression levels, while inhibiting pro-inflammatory cytokines TNF and IL6, as well as chemokines CCL2, CXCL5, and CXCL12 induction. Macrophages cultured in inflammatory substance-treated media from salivary gland organoid cultures exhibited pro-inflammatory polarization. However, treatment with dexamethasone shifted them towards an anti-inflammatory phenotype by reducing M1 markers (Tnf, Il6, Il1b, and Cd86) and elevating M2 markers (Ym1, Il10, Cd163, and Klf4). However, high-dose or prolonged dexamethasone treatment induced acino-ductal metaplasia and had side effects in both in vivo and in vitro models. Conclusions: Our findings suggest the effectiveness of corticosteroids in treating obstructive sialadenitis-induced salivary gland dysfunction by regulating pro-inflammatory cytokines.
Subject(s)
Dexamethasone , Kruppel-Like Factor 4 , Sialadenitis , Animals , Dexamethasone/pharmacology , Dexamethasone/therapeutic use , Dexamethasone/administration & dosage , Mice , Sialadenitis/drug therapy , Sialadenitis/pathology , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/therapeutic use , Disease Models, Animal , Organoids/drug effects , Cytokines/metabolism , Mice, Inbred C57BL , Salivary Glands/drug effects , Salivary Glands/pathology , Salivary Glands/metabolism , Salivary Glands/immunology , Aquaporin 5/metabolism , Aquaporin 5/genetics , Male , Macrophages/drug effects , Macrophages/immunology , Acinar Cells/drug effects , Acinar Cells/metabolism , Acinar Cells/pathology , HumansABSTRACT
Perilipins are evolutionarily conserved from insects to mammals. Drosophila lipid storage droplet-1 (LSD-1) is a lipid storage droplet membrane surface-binding protein family member and a counterpart to mammalian perilipin 1 and is known to play a role in lipolysis. However, the function of LSD-1 during specific tissue development remains under investigation. This study demonstrated the role of LSD-1 in salivary gland development. Knockdown of Lsd-1 in the salivary gland was established using the GAL4/UAS system. The third-instar larvae of knockdown flies had small salivary glands containing cells with smaller nuclei. The null mutant Drosophila also showed the same phenotype. The depletion of LSD-1 expression induced a delay of endoreplication due to decreasing CycE expression and increasing DNA damage. Lsd-1 genetically interacted with Myc in the third-instar larvae. These results demonstrate that LSD-1 is involved in cell cycle and cell death programs in the salivary gland, providing novel insight into the effects of LSD-1 in regulating salivary gland development and the interaction between LSD-1 and Myc.
Subject(s)
Cell Death , Drosophila Proteins , Larva , Salivary Glands , Animals , Salivary Glands/metabolism , Salivary Glands/cytology , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Larva/growth & development , Larva/metabolism , Larva/genetics , Drosophila/metabolism , Drosophila/genetics , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Drosophila melanogaster/growth & development , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-myc/genetics , DNA Replication , DNA-Binding Proteins , Oxidoreductases, N-Demethylating , Transcription FactorsABSTRACT
Sjögren syndrome (SS) is an autoimmune disease characterized by chronic inflammatory infiltrates in the salivary and lacrimal glands. Mucosal-associated invariant T (MAIT) cells are a subset of innate-like T-cells, predominantly found in mucosal tissues with crucial role in epithelial homeostasis. Thus, MAIT cells may be implicated in mucosal alterations of SS patients. Activation markers, inflammatory and cytotoxic cytokines were examined in 23 SS patients and compared to 23 healthy controls (HC). Tissular MAIT cells in salivary gland (SG) biopsies were also analyzed. Circulating MAIT cells were decreased in SS patients with a higher expression of CD69 and a higher CD4/CD8 ratio of MAIT cells. MAIT cells showed a higher production of IFNγ, TNFα and GzB in SS compare to HC. Tissular MAIT cells were present within inflamed SG of SS patients, while they were absent in SG of HC. Overall, circulating MAIT cells are decreased in the peripheral blood of SS albeit producing higher amounts of IFNγ, TNFα, and GzB. Tissular MAIT cells are detected in salivary glands from SS with a proinflammatory tissular cytokine environment. MAIT cells with abnormal phenotype, functions and tissular homeostasis may contribute to epithelial damage in SS.
Subject(s)
Mucosal-Associated Invariant T Cells , Salivary Glands , Sjogren's Syndrome , Humans , Sjogren's Syndrome/immunology , Sjogren's Syndrome/pathology , Mucosal-Associated Invariant T Cells/immunology , Mucosal-Associated Invariant T Cells/metabolism , Female , Middle Aged , Male , Salivary Glands/pathology , Salivary Glands/immunology , Salivary Glands/metabolism , Adult , Cytokines/metabolism , Aged , Case-Control StudiesABSTRACT
Irradiation (IR)-induced xerostomia is the most common side effect of radiation therapy in patients with head and neck cancer (HNC). Xerostomia diagnosis is mainly based on the patient's medical history and symptoms. Currently, no direct biomarkers are available for the early prediction of IR-induced xerostomia. Here, we identified PIEZO1 as a novel predictive tissue biomarker for xerostomia. Our data demonstrate that PIEZO1 is significantly upregulated at the gene and protein levels during IR-induced salivary gland (SG) hypofunction. Notably, PIEZO1 upregulation coincided with that of inflammatory (F4/80) and fibrotic markers (fibronectin and collagen fibers accumulation). These findings suggest that PIEZO1 upregulation in SG tissue may serve as a novel predictive marker for IR-induced xerostomia.
Subject(s)
Biomarkers , Ion Channels , Salivary Glands , Ion Channels/metabolism , Ion Channels/genetics , Biomarkers/metabolism , Salivary Glands/metabolism , Salivary Glands/radiation effects , Animals , Xerostomia/etiology , Xerostomia/metabolism , Mice , Male , Up-Regulation/radiation effects , Humans , Mice, Inbred C57BLABSTRACT
Coordinated cell shape changes are a major driver of tissue morphogenesis, with apical constriction of epithelial cells leading to tissue bending. We previously identified that interplay between the apical-medial actomyosin, which drives apical constriction, and the underlying longitudinal microtubule array has a key role during tube budding of salivary glands in the Drosophila embryo. At this microtubule-actomyosin interface, a hub of proteins accumulates, and we have shown before that this hub includes the microtubule-actin crosslinker Shot and the microtubule minus-end-binding protein Patronin. Here, we identify two actin-crosslinkers, ß-heavy (H)-Spectrin (also known as Karst) and Filamin (also known as Cheerio), and the multi-PDZ-domain protein Big bang as components of the protein hub. We show that tissue-specific degradation of ß-H-Spectrin leads to reduction of apical-medial F-actin, Shot, Patronin and Big bang, as well as concomitant defects in apical constriction, but that residual Patronin is still sufficient to assist microtubule reorganisation. We find that, unlike Patronin and Shot, neither ß-H-Spectrin nor Big bang require microtubules for their localisation. ß-H-Spectrin is instead recruited via binding to apical-medial phosphoinositides, and overexpression of the C-terminal pleckstrin homology domain-containing region of ß-H-Spectrin (ß-H-33) displaces endogenous ß-H-Spectrin and leads to strong morphogenetic defects. This protein hub therefore requires the synergy and coincidence of membrane- and microtubule-associated components for its assembly and function in sustaining apical constriction during tubulogenesis.
Subject(s)
Actins , Drosophila Proteins , Drosophila melanogaster , Microtubules , Morphogenesis , Spectrin , Animals , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Spectrin/metabolism , Spectrin/genetics , Microtubules/metabolism , Actins/metabolism , Drosophila melanogaster/metabolism , Microfilament Proteins/metabolism , Microfilament Proteins/genetics , Filamins/metabolism , Filamins/genetics , Salivary Glands/metabolism , Salivary Glands/embryology , Salivary Glands/cytology , Cell Shape , Cell Polarity , Actomyosin/metabolism , Microtubule-Associated ProteinsABSTRACT
SjÓ§gren's syndrome is a systemic autoimmune disease primarily targeting the salivary and lacrimal glands. Our previous investigations have shown that administration of interleukin-22 (IL-22), an IL-10 family cytokine known for its complex and context-dependent effects on tissues, either protective- or detrimental, to salivary glands leads to hypofunction and pathological changes of salivary glands in C57BL/6 mice and in non-obese diabetic (NOD) mice, the latter being a commonly used model of SjÓ§gren's syndrome. This study aims to delineate the pathophysiological roles of endogenously produced IL-22 in the development of salivary gland pathologies and dysfunction associated with SjÓ§gren's disease in the NOD mouse model. Our results reveal that neutralizing IL-22 offered a protective effect on salivary gland function without significantly affecting the immune cell infiltration of salivary glands or the autoantibody production. Blockade of IL-22 reduced the levels of phosphorylated STAT3 in salivary gland tissues of NOD mice, while its administration to salivary glands had the opposite effect. Correspondingly, the detrimental impact of exogenously applied IL-22 on salivary glands was almost completely abrogated by a specific STAT3 inhibitor. Moreover, IL-22 blockade led to a downregulation of protein amounts of Ten-Eleven-Translocation 2, a methylcytosine dioxygenase critical for mediating interferon-induced responses, in salivary gland epithelial cells. IL-22 neutralization also exerted a protective effect on the salivary gland epithelial cells that express high levels of surface EpCAM and bear the stem cell potential, and IL-22 treatment in vitro hampered the survival/expansion of these salivary gland stem cells, indicating a direct negative impact of IL-22 on these cells. In summary, this study has uncovered a critical pathogenic role of the endogenous IL-22 in the pathogenesis of Sjögren's disease-characteristic salivary gland dysfunction and provided initial evidence that this effect is dependent on STAT3 activation and potentially achieved through fostering Tet2-mediated interferon responses in salivary gland epithelial cells and negatively affecting the EpCAMhigh salivary gland stem cells.
Subject(s)
Interleukin-22 , Salivary Glands , Sjogren's Syndrome , Animals , Female , Humans , Mice , Disease Models, Animal , Interleukins/immunology , Interleukins/metabolism , Mice, Inbred C57BL , Mice, Inbred NOD , Salivary Glands/pathology , Salivary Glands/immunology , Salivary Glands/metabolism , Sjogren's Syndrome/immunology , STAT3 Transcription Factor/metabolismABSTRACT
Whole-exome sequencing of two unrelated kindreds with systemic autoimmune disease featuring antinuclear antibodies with IgG4 elevation uncovered an identical ultrarare heterozygous TNIP1Q333P variant segregating with disease. Mice with the orthologous Q346P variant developed antinuclear autoantibodies, salivary gland inflammation, elevated IgG2c, spontaneous germinal centers and expansion of age-associated B cells, plasma cells and follicular and extrafollicular helper T cells. B cell phenotypes were cell-autonomous and rescued by ablation of Toll-like receptor 7 (TLR7) or MyD88. The variant increased interferon-ß without altering nuclear factor kappa-light-chain-enhancer of activated B cells signaling, and impaired MyD88 and IRAK1 recruitment to autophagosomes. Additionally, the Q333P variant impaired TNIP1 localization to damaged mitochondria and mitophagosome formation. Damaged mitochondria were abundant in the salivary epithelial cells of Tnip1Q346P mice. These findings suggest that TNIP1-mediated autoimmunity may be a consequence of increased TLR7 signaling due to impaired recruitment of downstream signaling molecules and damaged mitochondria to autophagosomes and may thus respond to TLR7-targeted therapeutics.
Subject(s)
Autoimmune Diseases , DNA-Binding Proteins , Immunoglobulin G , Myeloid Differentiation Factor 88 , Toll-Like Receptor 7 , Animals , Immunoglobulin G/immunology , Immunoglobulin G/metabolism , Humans , Toll-Like Receptor 7/metabolism , Toll-Like Receptor 7/genetics , Toll-Like Receptor 7/immunology , Mice , Myeloid Differentiation Factor 88/metabolism , Myeloid Differentiation Factor 88/genetics , Autoimmune Diseases/immunology , Autoimmune Diseases/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Female , Male , Signal Transduction , Mitochondria/metabolism , Exome Sequencing , Antibodies, Antinuclear/immunology , B-Lymphocytes/immunology , Mice, Knockout , Mice, Inbred C57BL , Germinal Center/immunology , Pedigree , Salivary Glands/immunology , Salivary Glands/metabolism , Salivary Glands/pathology , Membrane GlycoproteinsABSTRACT
The larvae of Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), the swede midge, targets the meristem of brassica crops where they induce the formation of galls and disrupt seed and vegetable production. Previously, we examined the salivary gland transcriptome of newly-hatched first instar larvae as they penetrated the host and initiated gall formation. Here we examine the salivary gland and midgut transcriptome of third instar larvae and provide evidence for cooperative nutrient acquisition beginning with secretion of enzymes and feeding facilitators followed by gastrointestinal digestion. Sucrose, presumably obtained from the phloem, appeared to be a major nutrient source as several α-glucosidases (sucrases, maltases) and ß-fructofuranosidases (invertases) were identified. Genes encoding ß-fructofuranosidases/invertases were among the most highly expressed in both tissues and represented two distinct gene families that may have originated via horizontal gene transfer from bacteria. The importance of the phloem as a nutrient source is underscored by the expression of genes encoding regucalcin and ARMET (arginine-rich mutated in early stages of tumor) which interfere with calcium signalling and prevent sieve tube occlusion. Lipids, proteins, and starch appear to serve as a secondary nutrient sources. Genes encoding enzymes involved in the detoxification of glucosinolates (myrosinases, arylsulfatases, and glutathione-S-transferases) were expressed indicative of Brassicaceae host specialization. The midgut expressed simple peritrophins and mucins typical of those found in Type II peritrophic matrices, the first such description for a gall midge.
Subject(s)
Diptera , Larva , Salivary Glands , Animals , Salivary Glands/metabolism , Salivary Glands/enzymology , Larva/genetics , Larva/metabolism , Larva/growth & development , Diptera/genetics , Diptera/enzymology , Diptera/metabolism , Transcriptome , Digestion , Genomics , Gastrointestinal Tract/metabolism , Insect Proteins/metabolism , Insect Proteins/geneticsABSTRACT
The abusive use of anabolic androgenic steroids has become a serious health problem worldwide, but its effects on oral health are still poorly understood. Therefore, the objective of this study was to evaluate the effects of a supraphysiological dose of testosterone cypionate (TC) on salivary biochemical, histomorphology, immunohistochemistry, and redox state parameters of parotid and submandibular glands. Twenty male Wistar rats, 12 weeks old, were divided into two groups (n=10/group): a control group and TC group, which received a dose of 20â¯mg/kg, once a week, for 6 weeks. Post treatment, the saliva and glands were collected. A supraphysiological dose of TC increased plasma and salivary testosterone concentrations. Although TC did not alter salivary flow, pH, and buffering capacity, the treatment increased the salivary secretion of total protein and reduced amylase, calcium, phosphate, and potassium. TC reduced the connective tissue area in the parotid gland and acinar area of the submandibular gland, while increasing the granular convoluted tubule area in the submandibular gland. Proliferating cell nuclear antigen was higher in the acinar cells of the submandibular glands from the TC group. Moreover, TC increased concentrations of total oxidant capacity and damaged lipids in both salivary glands, while total antioxidant activity and uric acid were lower in the submandibular gland, and reduced glutathione was higher in both glands. Superoxide dismutase, catalase, and glutathione peroxidase activities were higher in the parotid gland, while only glutathione peroxidase activity was lower in the submandibular gland of the TC group. In conclusion, TC abuse may be a potential factor for dysfunction of the parotid and submandibular glands, becoming a risk factor for the oral and systemic health of users.
Subject(s)
Rats, Wistar , Saliva , Salivary Glands , Testosterone , Animals , Male , Testosterone/analogs & derivatives , Testosterone/blood , Rats , Salivary Glands/drug effects , Salivary Glands/metabolism , Saliva/metabolism , Parotid Gland/drug effects , Parotid Gland/metabolism , Submandibular Gland/drug effects , Submandibular Gland/metabolismABSTRACT
Salivary gland homeostasis and regeneration after radiotherapy depend significantly on progenitor cells. However, the lineage of submandibular gland (SMG) progenitor cells remains less defined compared with other normal organs. Here, using a mouse strain expressing regulated CreERT2 recombinase from the endogenous Tert locus, we identify a distinct telomerase-expressing (TertHigh) cell population located in the ductal region of the adult SMG. These TertHigh cells contribute to ductal cell generation during SMG homeostasis and to both ductal and acinar cell renewal 1 year after radiotherapy. TertHigh cells maintain self-renewal capacity during in vitro culture, exhibit resistance to radiation damage, and demonstrate enhanced proliferative activity after radiation exposure. Similarly, primary human SMG cells with high Tert expression display enhanced cell survival after radiotherapy, and CRISPR-activated Tert in human SMG spheres increases proliferation after radiation. RNA sequencing reveals upregulation of "cell cycling" and "oxidative stress response" pathways in TertHigh cells following radiation. Mechanistically, Tert appears to modulate cell survival through ROS levels in SMG spheres following radiation damage. Our findings highlight the significance of TertHigh cells in salivary gland biology, providing insights into their response to radiotherapy and into their use as a potential target for enhancing salivary gland regeneration after radiotherapy.